Over the past 15 years, we have made significant progress in the study lf language and affective development in children with congenital injuries to one side of the brain (FL). In each behavioral , we have covered evidence of initial deficits, and specific effects of lesion side and site, but these initial deficits are followed by substantial recovery and development, providing strong evidence for behavioral and neural plasticity in this population. Furthermore, we have shown that trajectories of deficit and recovery differ across domains. In language, lesion- symptom correlations exist in the first years of life, but they do not resemble the patterns observed in adults; by 5-7 years of age, specific effects of lesion side and site seem to have disappeared altogether. In spatial cognition, lesion-symptom correlations persist across childhood and adolescence, albeit in a mild form, and continue to resemble the correlations observed in adults. These results are compatible with a large literature on plasticity and reorganization in animals, supporting the view that brain development is a dynamic, responsive and self-organizing system. But they also offer a unique perspective on plasticity and brain organization in humans. We are now well-positioned to take a historic new steps, with convergent use of functional magnetic resonance imaging (fMRI), event-related brain potentials(ERP), combined with analogous "on-line" (timed" behavioral studies of language, spatial cognition and spatial attention. These convergent methods will yield unprecedented information about the "alternative brain plans" that have emerged across the course of development in children with FL. E will also continue to chart language and cognitive development into adolescence, using benchmark "off-line" (untimed" measures of language (including aspects of discourse that re critical to success in school and work), visual-spatial cognition, memory and executive function. On all measures, results for children with FL will be compared systematically to findings for children in other populations, including Specific Language Impairment, Williams Syndrome, Down Syndrome, and new project studying other forms of FL.